I think position is pretty important for this. I messed around with slight alterations to the movie, and it seems that where I move affected when to pop out. In particular, vertical position seems important. Horizontal position doesn't seem to really matter.
EDIT: even more footage:
this confirms to me that the other scorpion isn't a factor. Will mess around a lot with this one.
EDIT 2: From testing, horizontal position might matter? This is strange.
EDIT 3: I'm even more positive now that what is happening is a double hit of sorts. The scorpion will only fly in whatever direction he is facing when you hit him. However, if you get the quick kill, he flies up.
EDIT 4: Turns out a bunch of the movies I thought didn't save actually did and I wasn't waiting long enough before trying to play them again or looking in the wrong place.
EDIT 5: My current theory is that the scorpion still has a facing direction of sorts when attacking a boulder. When you get the quick kill, you are hitting it when it's direction is shifting to face you.
EDIT 6: Some more videos I have of it:
EDIT 7: I'm almost positive that what it is is that you hit the scorpion on both the top and bottom or left and right sides of it. You want to pop out of the ground right as you are passing over the imaginary line that divides the sections. Keep in mind that momentum is a thing.
EDIT: even more footage:
this confirms to me that the other scorpion isn't a factor. Will mess around a lot with this one.
EDIT 2: From testing, horizontal position might matter? This is strange.
EDIT 3: I'm even more positive now that what is happening is a double hit of sorts. The scorpion will only fly in whatever direction he is facing when you hit him. However, if you get the quick kill, he flies up.
EDIT 4: Turns out a bunch of the movies I thought didn't save actually did and I wasn't waiting long enough before trying to play them again or looking in the wrong place.
EDIT 5: My current theory is that the scorpion still has a facing direction of sorts when attacking a boulder. When you get the quick kill, you are hitting it when it's direction is shifting to face you.
EDIT 6: Some more videos I have of it:
EDIT 7: I'm almost positive that what it is is that you hit the scorpion on both the top and bottom or left and right sides of it. You want to pop out of the ground right as you are passing over the imaginary line that divides the sections. Keep in mind that momentum is a thing.